Mechanism for forming ends of metallic cylinders



June 28, 1960 R. KARGARD ETAL 2,942,567

MECHANISM FOR FORMING ENDS OF METALLIC CYLINDERS Filed Aug. 20, 1957 3 Sheets-Sheet 2 ZZZLE Faymozzd ffargara Peler [(zzrgara A//ezz U. [(argara HZ/mar A.- Andresen Fay and H. Andresen & L fi $4 kyruflfiy June 28, 1960 R. KARGARD ET AL 2,942,567

MECHANISM FOR FORMING ENDS OF METALLIC CYLINDERS Filed Aug. 20, 1957 3 Sheets-Sheet 3 Raymond [(argara Pe/er [far ara Allen 6. argard Hi/mar g. zlzyre seu w A4. z 78a zzzozzd 1? resezz b 71 7 fl M y H [2 5 5 v LVEILZZZE States MECHANISM FOR FORMING ENDS F METALLIC V CYLINDERS Filed Aug. 20, 1957, Ser. No. 679,222

4 Claims. c1. 113-52 The present invention relates to improvements in metal forming apparatus and more specifically to a mechanism for closing the end of a length of hollow cylindrical metal tube.

In metal forming and spinning operations, the ductility of the metal is usually. taken advantage of by stretchingthe metal into the forms required. In most instances, it is impractical to roll from a large diameter to a small diameter and this requires swaging in a manner that increases the thickness of the metal at the small diameter. The present invention contemplates providing amechanism capable of producing a closure at the end of a tube and particularly capable of producing a closure on the end of a tube, such as a thin wall welded tube.

Articles of this nature have been formed heretofore by j 0 forming a curved cup which is welded to the end of a cylindrical tube to complete the article. This method has been objectionable in that the product contains an unsightly weld, and that the manufacture requires an additional part. The present invention, therefore, con templates improving the product and reducing the time and cost of manufacture by spinning or rolling the end of the cylindrical tube into the required shape with the article being formed of a single unitary section of material.

In one form of mechanism embodying the principles of the invention, a plurality of shaped form rollers having a curved grooved surface are radially disposed in circumferentially spaced open arrangement to rotate freely on canted axes which are set at an angle to the axis of a cylindrical tubular workpiece that is to be fed to the rollers to have the end formed and closed. Between the rollers is a support spider having arms carrying bronze atent faced concave support surfaces which hold the area of metal of the cylinder between the rollers in non-galling engagement. The cylindrical tubular workpiece is moved against the rollers and a circular form mandril moved axially toward the rollers within the workpiece with the form mandril having a rounded face to coact with the rollers. The form mandril is stopped spaced from the rollers and thetube forced therebetween by afeed plate while the rollers and support spider are revolved about the axis of the cylindrical workpiece.

It is an object of the invention to provide a mechanism of the above nature which provides improved apparatus for forming and closing the end of a hollow elongated cylindrical tubular workpiece.

Another object of the invention is to provide an improved mechanism which will form a hollow tubular section of material with a closed end formed of a single unitary material, and shaped by decreasing the thickness of the tube in a progressive manner to form a curved closed end. 1

Another object of the invention is to provide an improved mechanism closing the end of a cylindrically shaped tube employing spaced formed rollers with means for preventing the metal from bulging between the rollers and for engaging the metal without galling the surface.

ice

Another object of the invention is to provide an im-g proved mechanism for closing the end of a tubular cylinder wherein opposed forming surfaces are employed which are" shaped to be spaced from each other in an increasing thickness following the curvature of the ma terial of the cylinder in an inward direction. Other objects and advantages will'become more ap parent with the teaching of the principles of the inven- I tion in the disclosure of the preferred embodiments in the specification, claims and drawings, in which:

Figure 1 is an elevational viewofa machine embodying the principles of the invention;

Figure 2- is a vertical sectional view taken through the machine embodying the principles of the invention and showing a tubular workpiece in place for operation of ,the machine, and taken along line II-H of Figure 4;

Figure 3 is a vertical sectional view similar to Figure 2 and showing the end of the tubular workpiece being formed:

Figure 4 is a horizontal sectional view taken through the machine, and illustrating the relative arrangement of the foiming rollers and support shoes; and,

Figure Sis a vertical sectional view taken along line VV of Figure 4, with parts being removed for clarity.

The apparatus and method embodying the features of the invention are illustrated in connection with Figures 1 through '5, as used for forming and closing the end of a length of a hollow tubular cylinder 6, as shown in,

Figures 2 and 3. The tubular cylinder 6 may be constructed of a material such as brass, steel, or aluminum and may be a section of seamless tubing-such as is available commercially. While the invention is well adapted to handling tubing of various sizes and thicknesses, by way of example, a tube on the order of six inches in diameter may have the end closed inwardly to form an article such as a fire extinguisher tank. In this case a welded steel tube provides suitable material. It will be understood, however, various articles may be formed and the apparatus disclosed as embodying the principles of the invention is shown and described by wayof illustration, and the features and elements of the invention may be used in other environments taking advantage of their inherent capabilities.

To form the tube by closingthe end, the end 8 of the tube 6, Figure 2, is curved inwardly to complete the inwardly formed closed rounded end 10 which is shown in Figurer3.

The forming mechanism includes a plurality of shaped i forming rollers 12, 14, 16 and radially of a center axis 20 of 18 which are disposed shown inlFigure 2 as it is advanced axially, which isin a downward direction as illustrated in Figures 2 and 3; The rollers 12, 14, 16 and 18 are supported for free rotation about canted axes on hearing posts' 22, 24,26

and 28u The bearing posts are mounted on a base SO 'and extend upwardly and outwardly to rotatably supportthe support shoes 38, 40, 42 and 44. Each of these shoes has a soft facingwhich is preferably of bronze with the facings beingillustrated at 46, 48 50 and 52, in Figures "1 4 and 5. The bronze shoe facings have inwardly curved surfaces which are curved in two planes so as to relatively "accurately fit against the curved end 10 of thetubul-ar Patented June. 28, 1960 p the tubular cylindricalworkpiece 6. The rollers are circumferentiallyarranged "and spaced in an open fashion so as to face upwardly to' be engaged by the lower edge 8 of the tube in the'm'anner axially in a direc- The shoesare supported vin .their.circumferentially ar-.

ranged spaced ,locationbetweenthe rollerson legs, such as shown at 52 and 54 for the shoes 38 andAZ. inFigure 5. The legs are part of a main support spider. .56" which is supported coaxiallywith the center of the tubular. workpiece 6 to properly locate and space the shoes. The

spider is illustrated as havinga centrally located hole 58 which permits it to beslid over a cylindricalboss or stop 69 projecting-upwardly from the base .3(l.l The;centr ally located stop 60, therefore, locates ,the:spider:and..has an upwardly facing stop., surface;62,,,which provides a limit for the downward axial movementof a form mandril 64.

The form mandril includes anenlarged end66 carried at the end of a support rod 68. Theform mandril has a leading downwardly facing rounded end which has a flat center portion '70, and which has an annular rounded The rounded edge surface 72 cooperatively edge 72. faces the inner facings 46, 48, 50 and 52 of the shoes, and also the surfaces of the rollers 12, 14, 16 and 18 to define a space therebetween for rolling and spinning the end of p the tubular cylinder 6.

For providing the end closing space for-the tube,

each of the rollers have-a concave annular grooved surface 74, such as illustrated for the roller 12 in Figure 1. This surface in profile has the same curvature as the facings for the shoes. The outer curved surface 72 of the form mandril is shaped to provide a forming spacefor the end of the cylinder workpiece 6 therebetween, and the width of the gap between the rollers or shoe facings and the form mandril increases movingdownwardly and erly space it from the rollers and from the support shoes.

The cylinder 6 is next axially thrust toward the rollers by axial movement of the feed plate 76 while simultaneously revolving the base 30 to carry the rollers around the tubular workpiece 6.,,.The cylinder 84 for operating the form mandril and the cylinders 83 and 85 for the feed pIatemaybe controlled manually or by automatic con-,.

trols through mechanism which. may be adopted by those diameter of the tube isaccommodated in increased thick-,-

ness. This is caused by forcing the metal between the rollers and form mandril by forcing the; cylinder 6 in a downward axial direction while preventing bulging be tween the rollers by the shoes.

The axial movement of the cylinder workpiece, 6 is caused by a feed plate 76,v shown as-havinga flat lower surface 78. A radial annular face 77 projects from below the surface 78 to center the tubular workpiece 6. The

feed plate is illustrated by way of example as being cir-v cular in shape and mounted coaxially with the rod 63 1 carrying the form mandril 66 The plate 76 isjsupported on a pair of push rods '79 andSl which connect to pistons slidable in fluid cylinders 83 and 85. The cylinders are fixed in position being supported at 80 and are provided with connections for receiving a supply of operatingfluid under pressure.

The tubular workpiece 6 is firstset in place with theend 8 engaging the rollers: 12, 14,-16 and 18,;as shown in Figure 2. The form mandril 66 is ,then moved axially along its axis 20-toward-the .openlyarranged upwardly facing rollers. over the form mandril, or the-form mandril inserted fromv the end after it is positioned. For axial movementofthe form mandril, the supporting rod-=68 may beconnected to a. rod 76, Figure 1, connectedto a piston housed within a fluid operated cylinder .84, which is anchored at-Sil. Suitable fluid lines lead to the-cylinder 78 in a manner to cause reciprocation thereof, and piston within the cylinder 78 is- .controlled,- thus-moving the piston rod 76 to 'position the {form mandril. the-form mandril is moved downwardly, its lower-flat surfaceflfl'engages the,upper;end'62 of thestop 60 to prop;

The tubular workpiece 6 may be;fir st slid bycontrol valves the When ' skilled in, the art following the teachings of the present,

disclosure.

For revolving the-base 39 to carry the rollers around the tubular, workpiece 6, the base may besupported on a lower shaft 86 for rotation about the vertical axis 20 of the workpiece. The base may carry a ring gear 88 which is driven by a mating piniongear i i carried on a drive shaft 92 of a motor 94. Themotor may be electrically operated at the proper time and may be operated at a desirable speed for forming the end of the tubular workpiece 6. The rollers 12 which are mounted for free rotation on their posts, will form and close the end of the workpiece 6 as it is thrust axially in the space between the rollers and the form mandril with the support spider being rotated on the base with the rollersand preventing the metal from bulging out between the rollers.

lt'will be understood that the operating mechanisms for the form mandril 65, feed plate 76, and base 30, are

drive devices may be readily adapted to operate the elements as described.

For each successive cylinder which is formed by having its end closed, the cylinder is positioned in its axial position against, the rollers, and the form mandril 66 advanced against the stop 6th The feed plate 76 will then force the cylindrical workpiece 6 axially against the rollers 12, 14, 16 and 18. The rollers and the support plates 38, 40, 42 and 44 are rotated about the stationary workpiece 6 and the form mandril 66 to gradually form andclose the end of the cylindrical workpiece 6.

Thus, it will be seen that we have provided an improved mechanism for fonning the ends of metallic cylinders which meetsthe objectives and advantages hereinbefore set forth. The mechanism is well adapted for commercial operation and the methods are susceptible of use for numerous applications and purposes.

The method and apparatus of the invention form a completed closed end for a cylinder, and operate to close the end of cylinders in varying desired amounts. The completed cylinder presentsa finishedsmooth article whichis not marred by welds, and is quickly and inexpensively manufactured with the utilization of a single part, and with the end being made of the cylinder material.,

We have, in the drawings and specification, presented a ,detailed disclosure of the preferred embodiments of ourinvention and it is to be understood that we do not intend to limit the invention to the specific form'disclosed, but intendto cover all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by our invention;

'We claim as our invention:

1. .A mechanism for forming and closing the end of a hollow tubular elongated cylinder whichcomprisesa plurality of radially disposed circumferentially spaced rollers having annular concave formingsurfaces and mounted for rotationabont axes canted with respect to a feeding axisfor a hollow cylindrical workpiece {to-be formed, individual support members between each of-the rollers having diametral spacing equal tothe rollers,- curved arcuate bronze cylinder engaging surfaces on the support members for sliding engagement in a non-galling manner witlrthe closing end of the cylinder, a spider having an axial centerwithradially extending arms carrying the support members with ,the-bronzefacings projecting be-.

" Lu o surfaces of the rollers and supporting members to form the closed end of the workpieces therebetween, means for moving the form mandril toward the rollers to an op erating position with a work forming space between the mandril and rollers, a stop means located between the rollers for engagement by the form mandril and positioned to stop the axial movement of the form mandril'in said operating position with the proper spacing relative to the rollers, a feed plate adapted to axially engage the end of the cylinder workpiece and moving axially to force the cylinder end between the rollers and form mandril after positioning the mandril in said operating position, and means for simultaneously rotating the rollers and support spider whereby the bronze facing of the supporting members will slidingly engage the cylinder preventing bulging while the rollers are forming the cylinder end against the form mandril.

2. A mechanism for closing the end of a tubular cylinder which comprises a plurality of radially disposed circumferentially spaced shaped rollers located in open relationship facing axially for receiving the axially moved end of a tubular cylindrical workpiece and having inwardly axially open endwise facing arcuate forming surfaces, a form mandril having an annular arcuate convex forming surface facing the rollers and having a diameter to fit the interior of a hollow cylindrical tubular workpiece, means for positioning the form mandril in a forming position to provide a work forming space between the mandril and rollers, means for gradually relatively moving the tubular workpiece endwise over the mandril with said mandril in forming position into axial end forming engagement with the rollers with the inner surface of the workpiece supported by the forming surface of the mandril, and means for relatively rotating the rollers about the mandril forming surface whereby the end of the workpiece will be gradually and progressively formed in said work forming space.

3. A mechanism for closing the end of a tubular cylinder which comprises a plurality of circumferentially spaced rollers having a hollow curved groove in the surface and radially disposed to be located in an open axially facing position for receiving a cylindrical tubular workpiece in an endwise fashion, support members having curved inwardly facing surfaces located between the spaced rollers to lend support to the material formed by the rollers, a form mandril having an annularly outwardly curved surface facing to cooperate with the rollers, means for moving the form mandril in an axial direction toward the rollers prior to advancing a tubular work- 7 piece against the rollers, astop'member for the form mandril positioned to terminate its axial movement ata forming position to'provide a work forming space be tween the mandril and rollers to. receive the wall material l of the. cylindrical workpiece therebetween with the inner surface of the workpiece supported by the curved surface of the mandril, means for advancing a workpiece axially over the mandril into said work forming space, and means for rotating the rollers and support membersrelatively around the mandril curved surface to form the end of the I 7 against which the end of the tube is formed, a plurality,

of curved grooved forming rollers facing the rounded surface of the form mandril with a forming space there between, supporting shoes positioned between the rollers to prevent bulging of the material as it is being formed,

the forming space between the rollers and form mandril being increasingly greater in the radially inward direction to accommodate increased thickness of the tube material as it is formed inwardly, means for forcibly advancing a tube axially over the mandril into said forming space with'the inner surface of the workpiece supported by the rounded surface of the mandril, and means for relatively rotating the rollers and support shoes with respect to the tube material and form mandril.

References Cited in the file of this patent UNITED STATES PATENTS 582,472 Heese May 11, 1897 1,280,823 Oster Oct. 8, 1918 1,815,275 Sadler July '21, 1931 2,069,858 Squires Feb. 9, 1937 2,173,759 McClaskey Sept. 19, 1939 2,194,385 Dove Mar. 19, 1940 2,234,182 Lauer Mar. 1 1,1941 2,286,511 Schulenberg June 16, 1942 2,325,522 Lauer July 27, 1943 2,421,629 Langos June 3, 1947 2,448,983 Johnson Sept. 7, 1948 FOREIGN PATENTS 577,3:1 1 France Sept. 3, 1924 

